In the event of a disaster resulting in the uncontrolled dispersal of radionuclides into the environment, it is imperative that the human population in the vicinity be rapidly screened for internalized nuclear material. Surface smears and nasal swabs are effective as exposure diagnostics for only a short time, leaving the assay of bodily fluids such as urine as the most viable method for determining possible internalization of radionuclides that cannot be detected by standoff means (i.e. those not having gamma or strong beta emissions). The goal of this research effort is to develop and demonstrate advanced materials and methods that will enable rapid high-throughput determination of internalized radionuclides (and the subsequent dose). Initial work will focus upon actinides and 210 Po due to the high radiation doses they impart when internalized and, most significantly, the current inability to quickly and easily detect internalized alpha emitters using stand-off techniques. Our objective is to create a system which would allow for simple, minimally invasive, efficient and reliable capture of radionuclides expressed in urine (and perhaps other fluids such as blood) to aid in the rapid diagnosis of internalized radioisotopes. Direct assay of the radionuclide preconcentrating materials (in a carefully engineered format) would be achieved with commercially available equipment amenable to automation. The time and intensity of analysis could be dynamically adjusted as needed, to allow for performance ranging from rapid high-throughput screening (minutes) to more extensive trace level isotopic assay (lasting hours to days). The research is focused upon 3 aims: 1. To develop and evaluate advanced sorbent materials that will efficiently capture and concentrate radionuclides from human urine and blood to facilitate rapid analysis. 2. To develop methods for utilizing advanced sorbent materials to enable accelerated, noninvasive, high volume assays of radionuclides from human urine and blood. 3. Demonstrate diagnostic assays (fast general screening and trace isotopic) of (spiked) human urine and blood using the best materials and methods developed for the detection of priority radionuclides (actinides and Po) at relevant activity/action levels. The proposed work supports a number of stated NIAID needs such as "Development of minimally-invasive biodosimetric devices and techniques, high-throughput diagnostic systems to rapidly assess levels and types of radiation exposure..." The proposed work also aligns with the "NIAID Radiation Countermeasures Program places a strong emphasis on product development of treatments for radiation injury and biodosimetric techniques for triage of individuals with potential radiation exposure." The proposed research will develop and demonstrate advanced methods and materials that will enable high-throughput screening of large populations for radionuclides which may have been internally deposited in victims'bodies following a nuclear event. It is anticipated that this work will provide the technology for a simple noninvasive "self-sampling" device (such as a dip stick) for bodily fluids like urine that could be directly submitted for rapid (minutes) on-site screening of high exposures as well as more extensive measurement for the determination of trace levels of internalized nuclear material (and subsequent resulting radiation dose).